Thank you for the information.
Some say that fans in dynamic furnaces make a little noise and it can disturb, for example, in sleep.
It probably depends on the model. In my fan, you can only hear when you put your ear to the stove, or there is perfect silence around it, and it is barely audible anyway.
I am thinking of making a suspended ceiling of profiles + GK (lowering from 3.75m to 2.80m). Will then heating costs decrease by this cubature (i.e. 25%) - or something more?
On the other hand, it would be a bit of a regret to have a pleasant coolness in summer

Low height - not enough for an anstresol, and too much for an ordinary apartment